This invention relates to a fuel supply system including a fuel supply line extending from a fuel tank to a fuel supplier for delivery of fuel to an internal combustion engine and, more particularly, to a fuel supply system including a water separator positioned in the fuel supply line, the water separator having a chamber in which fueld and water are separated into a lower phase comprising water and an upper phase comprising fuel.
If water exists in fuel for an internal combustion engine, corrosion may occur on engine cylinder wall and in the fuel supply circuit including a fuel tank and fuel lines and, particularly for a diesel engine, baking may occur on parts moving at high speeds in the fuel injection pump. As a result of the baking, the fuel injection pump do not function in the most efficient manner with its fuel injection performance spoiled to increase the tendency of engine stalling and sometimes cease to function at all.
The conventional practice is to provide a water separator in the fuel supply circuit, for example, upstream of the fuel injection pump for diesel engines, to remove water from fuel prior to delivery to the fuel injection pump. The water separator has a water separating chamber in which fuel and water are separated into an upper phase comprising fuel and a lower phase comprising water due to the difference between fuel and water densities. The water separating chamber has a water level sensor associated with an electric circuit to actuate a warning light to urge the driver to drain the water out of the chamber when a predetermined water level is reached.
One difficulty with such conventional water separators is the danger of damaging the fuel injection pump or other engine elements. If the driver leaves the water without draining it from the water separating chamber in spite of the warning indication or if a great amount of water, stored in the fuel tank, flows at one time into the water separating chamber for any of reasons, water will overflow and enter the fuel injection pump, with a resulting failure of the fuel injection pump.
The present invention provides a fuel supply system including a water separator positioned in a fuel supply line extending from a fuel tank to a fuel supplier for delivery of fuel to an internal combustion engine wherein a warning indication is made for urging a driver to drain the water in the water separator when the water level in the water separator increases to a first level before communication is interrupted between the water separator and the fuel supplier when the water level in the water separator increases to a second level higher than the first level.